Carbon filtering adds flavor to spirit... Need help again...

So, i spent all weekend running 6 ferments thru the still twice each, and came up with about 8L of finished spirit. Of that I pulled and blended 5L of clean hearts from my cuts. So lots of work in this stuff.

I just ran a that batch thru a carbon filter rig with some activated carbon. For the second time it appears to be throwing a weird grapey-medicinal odor into the spirit upon exiting the filter column.

The first time (three weeks ago when I had some stunning clean wash to go thru) I thought the carbon was dirty from previous filtrations and had to dump 4L of 90% spirit. this time I cleaned out the column replaced the activated charcoal and then ran 1.5L of water thru to charge the carbon, then followed up with 5L of my best stuff. Sure as anything it threw that dam flavor into it again... with FRESH charcoal!!

Also, I note that the stuff with the stank is now cloudy, I recovered the 3L at least and I managed to get 2L out of the top of the filter before it went down, but I'm stumped ....

...why this is doing this?

Column setup is this:

top    = stainless funnel
middle = stainless 2" tube 36" long filled with activated charcoal for distilling
bottom = 10micron filter cloth wired around the exit which removes any charcoal dust

Potential answers I can come up with:

  1. as the alcohol comes down the colum it heats up pretty good, to maybe 120F then cools. the hotspot follows the alcohol down as it pushes the water out. This may be creating a flavor or something
  2. I didnt wash the charcoal this time. I did last time and it still threw the flavor tho. same charcoal batch.
  3. Maybe I didnt wash the tube well enough and it's pulling something off the surface.

the smell:

Some folks call it "tequila" another german called it "grappa", others still "medicinal". I say grapey medicinal with a hint of tequila (bad tequila tho). It's not there before filtering in any way, but after filtering it is.

Can you help me please? any ideas?

Best Answers


  • So, I have looked up my scripts from the MOB seminar: It should be 2 Butanol, which is produced when too old mash is distilled or chlorine or other disinfection cleaning agents where used. I guess you are still dealing with one and the same problem. If you only smell it after filtering, perhaps it is that way, becauser other smells are filtered away... my 2 cents.

    StillDragon Europe - Your StillDragon® Distributor for Europe & the surrounding area

  • edited June 2014

    Yes, Gert's book as an often mentioned classic (we already have a copy of the PDF available for download here in our forum, see the link above in @crystal_skull's comment). Have a look here as well:

    My StillDragon Activated Carbon Filter

    Your Place to be >>> <<< Home of the StillDragon® Community Forum

  • OK, It looks like I need to clean my carbon better before using it. apparently a simple vigourous rinsing is not enough t do it.

    As for bleach or other fermenting issues, the mash was distilled within hours of finishing (maybe before it was done), the fermenters were brand new never used buckets cleaned with soap and water only.

    I've since the last issue kinda solved the other smell. This is CLEARLY from the carbon as a clear spirit went in and a cloudy one came out.

    Trying boiling the carbon now to clean it better after repeated rinsing.

  • There are instructions for reusing carbon and re activation on the net if you search... it has to be boiled rinsed and then heated for extended times depending on quantities ... HD old home site has some instructions do a google of carbon reactivation...

    Good Luck


  • Gert Strands book does a decent job of explaining the process. Guess I missed that when I perused it the first time.

    Back to reading and boiling!!

  • A question... is it better to filter the 92% spirit or the 40% neutral?

  • Have read that it is most effective around 38%.

  • OK, so I followed the directions in that carbon guide. good stuff. kind of a pain tho. hopefully worth it!

    Started filtration this AM with-4-5L of 90%. ran it thru about 4 times and it cleaned up pretty good.

    Now I've cut the spirit with filtered water and am running it thru the carbon again. coming off much nicer and that funky smell seems to be finally gone completely after cutting and refiltering. I will know more after I have everything out of the filter and in containers ready to be processed.

    I've pulled and sampled the before and after and it's almost where I want it... a top shelf vodka. Much smoother with no off smells. I'll run it by a great pallette in town when I can and see what he says. if he gives the thumbs up then we are there!

    Fingers crossed!

  • ****#RedDoorDistillery I caught your comment before it disappeared. I believe that is exactly what is happening. in fact cleaning this carbon is very difficult and 8-12 rinses with 4 boiling water rinses barely takes out the chemicals.****

    Upon review of the product that came out looks like I have a mid shelf vodka, and somehow with spillage and multiple filterings, I turned 5L of 90% hearts into 6L of 35% vodka. Seems like I spilled a lot huh?

  • @Fiji_Spirits said: RedDoorDistillery I caught your comment before it disappeared.

    There (usually) are no disappearing comments here in our community. B-)

    The Ask a Question feature allows you to rate if a comment answers your questions or not. If you click the Yes below a comment it gets pulled up to the top below your initial posting. Those comments you consider a meaningful answer are listed in the section Best Answers (as seen here with the comments from @crystal_skull and @RedDoorDistillery) followed by Answers with the other comments not rated or rejected.

    Your Place to be >>> <<< Home of the StillDragon® Community Forum

  • Ahh.. see it now. didnt expect it to jump to the top.

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